Am 12.10.2017 um 20:37 schrieb sserg...@gmail.com: > Hi. > > Sorry for late message. But nobody still have said about possible problem > with > suggested patch.
Well, it's always very hard to review such highly optimized code. I had a look and tested it and it worked, I didn't notice the problem below either. > So I decide to pay attention on that proposed code may be > incorrect under some circumstances IMHO. > > Instruction on line 657 > > subq %rcx, %rax > > decreases value in %rax on %rcx, but previous code doesn't set any value to > 32 > high bits of %rax and 32 high bits of %rcx still contain 32 high bits of buf1 > address. So I think that correct result is not guarantied. > > I suggest to use mozbq instead of movzbl to fix this issue. I think also the final xor should be a xorq %rax,%rax, right? _______________________________________________ fpc-devel maillist - fpc-devel@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-devel
